Arthroscopic surgery, in which the intra-articular space is filled with fluid, allows orthopedists to efficiently perform procedures using special purpose instruments designed specifically for arthroscopy. Among these special purpose tools are various manual graspers and biters, electrosurgical devices, and powered shaver blades and rotary abraders. Shaver blades having hollow bores are typically removably coupled to a shaver handpiece and are used for cutting, resecting, boring, and abrading both soft and hard tissue at the surgical site. A rotary abrader (also known as a bur) generally includes a rotatable inner tube having an abrading head at its distal end and a fixed outer tube for rotatably receiving the inner tube. Abraders are used for abrading or shaping both soft and hard tissue as bone, cartilage or ligaments by use of the rotating abrading head.
Requirements for a rotary abrader for arthroscopy include a compact size so as to fit through small cannulae, a means for removal of debris, and a configuration which allows the surgeon to access structures within a joint, while retaining good visibility. Anatomical structures with various curvatures, such as the acetabulum in hip surgery, the talus in ankle surgery, the glenoid in shoulder surgery, and the notch in knee surgery are difficult to access with a straight bur and, if accessed, can cause excessive bending to the bur.
A surgical bur with an improved curved design that minimizes bur extrusion and increases the containment of the bur tip within the outer tube is needed. Also needed is a curved bur with a design that allows centering of the bur tip within the outer tube, while preventing bur wobble. A curved bur with a tip area that prevents extrusion of the bur from the outer hood during rotation is also needed.